Bag machine



y J. KOAENIG 2,123,508

BAG MACHINE Filed March 15, 1937 2 Sheets-Sheet l Jilly 12, 1938. J KOENlG 2.123.508

BAG MACHINE Filed Mafch 15. 19:57 2 Sheets-Sheet 2 25 Figs. 1 and 2;

Patented July 12, 1938 2,123,508

. UNITED STATES 'PATENT- OFFICE BAG MACHINE John Koenig, Philadelphia, Pa... assignor to Benjamin C. Betner Company, Devon, Pa a corporation of Delaware Application March .15, 1937, Serial No. 130,823 6 Claims. 93-27) My invention relates to machines for making As the drum I rotates in counterclockwise dipaper bags, and particularly to mechanism for rection the blank B whose flap F is held to the forming and closing the bottoms of bags. drum by fingers 4 is drawn upwardly beneath In accordance with my invention, the bag the weighted holding fingers 26 and concurrent-- 5 blank is held, to structure for carrying it adly the shaft 8 isrotated in opposite direction, the '5 jacent bottom-forming and closing mechanism, 'timing between the shafts being such that the by grippers at least one of whose jaws is protucker blade III engages the moving blank B vided with blunt abutments or projections which substantially along the line marked :c, Fig. 6, and clamp upon a crease in the bag blank forced forces the blank between the jaws of the gripper 10 between the jaws by a tucker blade having G which are at this time open. As movement of 10 notches in alignment with the projections on the drum I continues, the jaws of the gripper G are gripper jaws and which is withdrawn after the .closed by cam mechanism not herein disclosed, jaws have closed to clamp the bag blank. but generally as illustrated in the aforesaid Pot- My invention further resides in the features devin patent; the timing being such that the of construction, combination and arrangement tucker blade I 0 is withdrawn before or substan- 15 hereinafter described and claimed. tially concurrently with closure of the gripper For an understanding of my invention and for Jaws. illustration of a preferred form thereof, reference As drum I and shaftfi continue their rotation,

is made to the drawings in which: the second tucker blade II engages the blank B Fig. 1 is a plan view of bag-closing mechaalong the line marked 1/, Fig. 6, and forces the 20 nism; blank along this line between jaws of the gripper Fig. 2 is a side elevation, with parts in section, -GI which are opened somewhat before the blade of mechanism shown in, Fig. 1; and jaws are in substantiallyvertical alignment.

Fig. 3, in perspective, shows parts appearing in The blade II creases the blank at y and forces Fig. 4 is a section, on enlarged scale, illustrative a shallow but thick muiti-ply crease or fold. The of gripper mechanism shown in Figs. 1-3; gripper GI comprises a relatively stationary jaw I Fig. 5 is a detail, on enlarged scale, of cam member I2 carried by the arm I3 which is rotatstructure shown in Figs. 1-3; able with the drum but may be adjusted an- Fig.6 is a perspective view of a bag blank. gularly with respect thereto and a movable grip- 30 Referring to Figs. 1 and 2, the mechanism disper jaw II attached to shaft I 5 whichalso rotates closed is generally of the character illustrated with the-drum I. ,The gripper jaws I 2 and I 4 in Potdevin Patent #1,176,163 for forming and I are biased toward engagement with each other closing the bottom of a bag blank, for example, by' the powerful spring I6, one end of which is v of the well-known tubular type, such as blank IB suitably attached to shaft I5 and the other end 35 shown in Fig. 6 hereof. of which is secured to the drum I. Preferably,

The blanks are formed by mechanism not herethe tension of spring I5 is djustable to permit in disclosed, and each in turn is fed with'the flapF variation of the clamping pressure to suit bags thereof presented to the cylinder or drum I atof different grades and finish of paper. From the Y the crease between the gripper jaws thus to form 25 40 tached to shaft 2 which is supported by the side shaft I5 extends an arm I! having a cam fol- 40' frames 3 of the machine. The fingers 4 which lower or roller I8 in whose path of movement is extend through gap 5 in the periphery of the disposed the cam I9 adjustablysecured to a stadrum I clamp the flap F of the blank to the drum tionary member 3a attached to the machine for movement therewith as the drum rotates in frame. counterclockwise direction, as viewed in Fig.- 2. Cam I9 is so adjusted the jaws I2 and ll of 45 The fingers 4 are carried by blocks 6 on shaft I gripper GI are separated, as above stated, somewhich rotates with the drum 6 and is rocked in what before the bag blank B carried by drum I timed relation thereto by cam structure not herearrives at such position the tucker blade II enin shown, but whose construction and operation gages the blank along line 11. The jaws I2 and are well-known to the art as illustrated, forex- I4 remain separated until the tucker blade II 50 ample, by the aforesaid Potdevin patent. has pressed the crease at 1/ between the gripper.

To Sh t which 18 Supported above Shaft J ws; before the blade I I is withdrawn, the roller by the side frames 3, are secured the supporting I8 passes abruptly off the end of cam I9 to close v members 9, 9 which carry the tucker blades I I the Jaws upon the crease. and I I. As'most clearly appears from Figs. 1, 3 and 4, 55

the tucker blade II is provided with notches or recesses 2|] which are in alignment with blunted teeth or projections 2| which extend a short distance from the gripping surface of movable jaws |4 towards the gripping surface of the stationary jaw I2. By so constructing the gripper sible so to adjust the clamping pressure of the blank to release from the gripper G during with-' gripper jaws and the timing of the grippers and tucker blade that there is no tendency for the drawal of blade |0 or during the subsequent operations. However, at the crease y, the number of thicknesses of paper is materially higher, and is often or usually so great the thickness of the crease y, as shown in Fig. 4, is of the same order of magnitude as the depth of the crease with the result, and particularly when the paper is of waxed, lacquered or glazed finish, or when the external bag is of material, as cellophane, or the like, great difficulty has been experienced in so adjusting the machine that the bag blanks would not release at 1 during the bag-forming and closing operations. In general, the surfaces above mentioned have low coefficient of friction, and securely to hold the bag a high degree of pressure is required particularly because jaws of gripper GI, whether of the old or new construction, can at most merely nip the blank at crease 3 With prior constructions,

when the pressure was adjusted to value high enough to prevent the bag from following the blade as it was withdrawn, the surface of the.

bag was often badly marred or torn, whereas, unless high pressure were used, the bag would be insecurely clamped and would release during subsequent operations often with damage to the mechanism. It was .difiicult, and for some bag materials, practically impossible to obtain an optimum adjustment of the gripper corresponding in general purpose to Glhereof i furthermore, when'such' optimum adjustment was obtained, there was noassurance it would not be necessary to repeat the tedious procedure before the end of the run because of the eifeet of atmospheric conditions upon the bag material and/ or upon the machine parts.

With the gripper construction illustrated, the bag blank is securely held by the toothed projections 2| of gripper jaw l4 and thepressure' upon thecreasey is more or less, though not entirely, localized at these areas. The pressure at these points is not in full impressed upon the tucker blade I I because of notches 20 therein which are in alignment with the projections 2|.

Because the projections 2| extend but slightly from the gripping face of jaw I2 and .because of the yielding nature of the thick fold or crease y, the gripper jaws I2 and M are effective throughout their length to hold the crease y although the gripping pressure is at least initially higher at the blunt projections 2|. As the blade is withdrawn, the tendency of the blank to follow or tend to follow the tucker blade is insubstanaiaaaos the bag surface even when highly glazed.

' Preferably, as shown in Fig. 3, one and preferably both of the jaws of the gripper GI are divided, as by notches 25 from their outer edges, into several fingers; specifically, in Fig. 3, the fingers 22 of the movable blade |4 formed by the notches 23 in the blade are opposite or in alignment with the fingers 24 formed by the notches 25' in the fixed blade l2. The division of each of the gripper jaws |2, |4 into sections, which are at least to slight extent capable of relative fiexure, facilitates an adjustment of the mechanism which will permit the clamping pressure to be adjusted to value suitable to prevent the blank from following the tucker blade l3 as it withdraws from the crease,without being so high as to mar or mark the blank. When the jaws of gripper G| are closed upon fold or crease y,- all fingers of the jaws are effective to exert substantial clamping pressure upon the crease; spe- .14 which is devoid of projections 2| is effective to press that portion of crease y between projections 2| against the central section 24 of jaw l2, and the areas of the outer fingers 22 beyond the projections 2| are effective to press those portions of crease y beyond the projections 2| against the corresponding areas of the fingers 24 of the fixed jaw l2.

The mechanism for applying adhesive or paste to the portion b of the blank between the creases m and y, and for subsequently folding-the flaps F and Fl to seal the bottom of the bag, is not herein shown because it may be of known construction as exemplified, for example, by the aforesaid Potdevin patent; the flap F| is folded into engagement' with" the pastedsurface of the bottom section b of the bag by the folding bar 21 which extends between the chains 28, 28a adjacent the opposite side frames of the machine and engaged by sprockets 30, 3| on shafts 32, 33. The mechanism for applying the second flap F, not shown, may be of any suitabletype, such as illustrated, for example, in aforesaid Potdevin patent.

What I claim is:

1. A bag-forming machine comprising bagcloslng mechanism, structure for transporting a bag-blank toward said mechanism, means carried by said structure for clamping the leading end of said blank, mechanism securely to hold the for engagement by the gripping faces'thereof and by said projections therefr0m.,

2. A bag-forming machine comprising bagclosing mechanism, structure for transporting a bag-blank toward said mechanism, means carried by said structure for clamping the leading end of said blank, mechanism securely to hold'the bag-blank, for operation thereon of said bagclosing mechanism, without marring the bag comprising gripper jaws carried by said structure, at least one of said jaws having blunt projections extending from its gripping face toward the other Jaw for engaging the blank while held to said structure by said clamping means, blade structure, having notches straddling said projections, for tucking the blank, beyond the clamped leading end, between said gripper'jaws for engagement by the gripping faces thereof and by said projections therefrom, and means adjustable to determine the pressure of said gripper jaws on the tucked-in portion of the bag blank.

3. A bag-forming machine comprising structure for transporting a bag-blank, bag-closing mechanism operating upon said blank during its transport by said structure, mechanism to hold the bag-blank for operation thereon of said bag-closing mechanism comprising relatively movable gripper jaws carried by said structure, and blade structure for creasing the bag-blank during its transport by said structure to form a thick, multi-ply fold between said gripper jaws,

at least one of said jaws having projections ex-.

tending a short distance from its gripping surface toward the gripping surface of the other jaw to compress said thick fold at localized areas, said gripping surfaces exerting substantial pressure along said fold where not locally compressed by said projections, and said blade structure having notches to straddle those sections of the fold compressed by said projections.

4. A bag-forming machine comprising structure for transporting a bag-blank, bag-closing mechanism operating upon said blank during its transport by said structure, mechanism to hold the bag blank for operation thereon of said bagclosing mechanism comprising relatively movable gripper jaws carried by said structure, at least one of said jaws having slots subdividin it into gripping fingers, and blade structure for creasing the bag-blank during its'transport by said structure to form a thick, multi-ply fold between said gripper jaws, at least some of said fingers having projections extending from their gripping surface toward the gripping surface of the other jaw to compress said thick fold at localized areas, said fingers where devoid of projections exerting substantial pressure along said fold where not locally compressed by said projections, and said blade structure having notches to straddle those sections of the fold compressed by said projections.

5. A bag-forming machine comprising structure for transporting a bag-blank, blank-holding means movable with said structure comprising gripper jaws at least one of which has notches extending inwardly from the edge thereof, and at least one of which has blunt projectionsextending from its gripping face toward the other jaw, and blade structure for tucking the bagblank between said jaws having notches in substantial alignment with said jaw notches and for clearing said projections when the unnotched portions of the blade are embraced by unnotched portions of the jaws.

6. A bag-forming machine comprising a rotatable drum for transporting a bag-blank, blankholding means movable with said drum comprising gripper jaws at least one of which has ridges extending from its gripping face and in direction substantially radial to the axis of rotation of said drum and both of which have aligned slots adjacent said ridges, and blade structure for tucking the bag-blank between said jaws having notches for clearing said projections and unnotched sections which are embraced by those sections of the gripper jaws between the slots thereof.

' JOHN KOENIG. 

